1. Field of the Invention
The present invention is related to a cooling fan, and more particular to a cooling fan which is easy to assemble, has low-noise and has an effective lubricant seal.
2. Description of Related Art
A conventional cooling fan used for a computer is shown in FIG. 3. The fan comprises a housing (80) with a recess (not numbered). A seat (801) is formed at a bottom face of the recess of the housing (80). A circuit board (83) and a stator assembly (82) are fixedly provided on an outer periphery of a sleeve (81) secured on the seat (801). A self-lubricating bearing (88) is received in the sleeve (81), and a core (841) of a rotor (84) covering the stator assembly (82) is inserted in the bearing (88). A collar (87) is provided on a distal end of the core (841) to secure the rotor (84) in the bearing (88). Washers (85) and oil-seals (86) are respectively mounted on the core (841) at both ends of the bearing (88) to prevent lubrication leaking from the bearing (88). Finally, a sheet (89) is fitted on a bottom end of the sleeve (81) to seal the workings of the fan.
However, the conventional cooling fan has some shortcomings which are as follow:
1. When the fan is running, the washers (85) and the oil-seals (86) rotate with the core (841) of the rotor (84), and friction generated between the washers (85) and the sleeve (81), and the oil-seals (86) and the bearing (88) causes a large noise. PA1 2. Because the washers (85) and the oil-seals (86) are small elements, it is difficult to assemble them. Moreover, a special tool is needed to assemble the collar (87) on the core (841). PA1 3. The oil-seals (86) can not completely prevent the lubrication from leaking out.
Therefore, it is an objective of the invention to provide an improved cooling fan to mitigate and/or obviate the aforementioned problems.